Joining system for two building elements

ABSTRACT

The present invention relates to a joining system for securing a first building element ( 1 ) relative to a second build element ( 2 ), where a first part ( 10 ) comprises a box element ( 100 ) adapted to be cast in one of the building elements ( 1, 2 ). According to the invention a lifting element ( 110 ) is secured to the box element ( 100 ), which lifting element ( 110 ) comprises an attachment portion ( 111 ) adapted for cooperation with lifting equipment, which attachment portion ( 111 ) during an installation phase of the joining system is located relatively outside an outer side ( 3 ) of one of the building elements ( 1, 2 ) comprising the box element ( 100 ).

The present invention relates to a joining system for joining twobuilding elements where the joining system comprises an attachmentdevice for easy handling of the building elements which have to bejoined.

Such joining systems are normally used for joining a beam to a pillar oralternatively a step element in a staircase, or between two stepelements. In a variant the joining system may comprise a box elementmounted in the beam with a movable bridge element in the box element,which when the beam is lifted into the required position is guided outto an extended position where the bridge element abuts against anabutment surface in the pillar, holding the beam in place by means ofthe weight of the beam. The space between beam and pillar can then begrouted.

There are several alternative solutions for joining systems. Anotherexample is a hooking arrangement where the beam comprises a fasteningdevice which is unhooked from a hook secured to the pillar or viceversa.

In all these solutions attempts will be made to lift a building elementin order to position it in relation to the other building element withwhich it is to be joined. In order to construct large building, aplurality of lifting procedures will be required in order to lift allthe building elements into position.

The object of the present invention is to provide a solution wherebuilding elements which have to be lifted in an easy and safe manner canbe lifted for positioning relative to the building element with whichthey have to be joined. Another object is to provide a system which iscost-effective in production and use.

These objects are achieved with a joining system as indicated in thefollowing independent claims, where further aspects of the invention areindicated in the dependent claims and the description below.

The joining system according to the invention is employed for joiningand securing a first building element relative to a second buildingelement. These two building elements may, for example, be a beam and apillar or a step element and a staircase or two step elements. A firstpart of the joining system is mounted in one building element and asecond part of the joining system is mounted in the second buildingelement. Which part is mounted in which building element will depend onwhich building elements have to be joined and the situation in which thejoining system is employed.

According to the invention the first part comprises a box element,preferably cast in one of the building elements, where a lifting elementis secured to the first box element, which lifting element comprises anattachment portion which protrudes from an outer side of the buildingelement that has to be lifted. Alternatively, the box element may besecured to one of the building elements in another way, such as bywelding, screwing or the like. In this application an outer side shouldbe considered to be composed of the total surface of a side of theelement. This outer side or the total surface may be composed of a mainsurface and at least one partial surface located inside and/or outside aplane in which the main surface is located, viewed in relation to therest of the element, with the result that the partial surfaces may becomposed of recesses or raised portions. The outer side thereforecomprises both the main surface and the partial surfaces.

The attachment portion may be composed of a simple lift eye, athickening portion, which may for example be spherical, more conicallyshaped, cube-shaped or be of another shape which may, for example, be acombination of the above or another shape, a hook portion, alternativelyit may form a lift eye, thickening portion, hook portion, which ishinged relative to the rest of the lifting element, or alternativelyanother rapid coupling part for cooperation with an opposite rapidcoupling part in the lifting equipment which has to lift the buildingelement. A variant may also be envisaged where a lifting elementcomprises several attachment portions.

The lifting element may be secured to the box element in several ways,such as for example being welded to the box element before the boxelement is cast in the building element. Alternatively, the liftingelement may be designed so that it is inserted in the box element beforebeing cast in the building element which has to be lifted. In yetanother variant, threaded portions may be provided on the box elementwhere the lifting element is provided with interacting threads, thusenabling it to be screwed to the box element. In a variant the liftingelement may be secured to a top wall of the box element, and in anothervariant it may be secured to a side wall of the box element. By havingthe lifting element secured to the box element before casting, a secureattachment of the lifting element will be achieved, while at the sametime good force transfer is obtained from the lifting element via thebox element and on into the building element that has to be lifted. Itis also conceivable for several lifting elements to be secured to thesame box element, where these several lifting elements may be mounted onthe same side of the box element or on different sides, or with some onone side and some on another side.

The attachment portion of the lifting element will necessarily belocated outside an outer side of the building element that has to belifted after it has been cast. This can be achieved in several ways, oneof which is that the attachment portion protrudes outside a main surfaceof the building element, in which case the main surface forms theoutside of the building element. In another variant this can be achievedby the attachment portion of the lifting element being located in arecessed portion of the building element relative to a main surface ofthe rest of the building element, whereby it is still located outside anouter side of the building element, while at the same time it is withina surface coinciding with a main surface of the building element. Bygrouting the space between the building elements that have to be joined,which is a normal procedure in such joining systems, this recessedportion of the building element can also be grouted, thereby providing asmooth uniform surface for the building element which was lifted. Thissurface will then normally be located in the same plane as the mainsurface of the building element. This recessed portion of the buildingelement, which forms a partial surface, may be in the form of astep-down of the building element towards the end facing the otherbuilding element to which the first building element has to be attached,or a type of cavity may be envisaged in the main surface of the castbuilding element. This cavity may have a partly conical shape with thelifting element positioned substantially in the centre of the conicalshape. Alternatively, the cavity may be provided with lead-in portionsadapted for leading the lifting equipment in towards the attachmentportion of the lifting element for easy joining thereof. In anembodiment this may be implemented, for example, if the attachmentportion is a fixed ring, where the cavity is composed of two cavityportions leading in towards the hole in the fixed ring. This will guidea hook in towards the attachment portion of the lifting element. Theconical shape will also help to guide the lifting equipment into thecorrect position with the attachment portion.

During use the attachment portion will normally be located at asubstantially horizontal side of the building element, which horizontalside faces relatively upwards in relation to the rest of the buildingelement. This facilitates the use of the attachment portion and theinteraction of this attachment portion with any lifting equipment, whichwill often be a lifting crane.

The fact that the attachment portion is located in a relatively recessedportion of the building element also means that during transport thebuilding element has no protruding parts outside a main surface of thebuilding element, which is advantageous.

According to an aspect of the invention the box element has an open endand the first part of the joining system further comprises a travellingbridge element inside the box element, and internally movable between aretracted position substantially arranged inside the box element and anextended position where a portion of the bridge element is locatedoutside the open end of the box element. The box element's open end ispreferably arranged with the plane of the open end aligned with an outersurface of one of the building elements, with the result that it doesnot protrude outside a main surface of this side of this buildingelement. This outer surface, with which the box element is aligned, willnormally be a different outer surface of the building element that hasto be lifted from the surface where the attachment portion of thelifting element is located. For a concrete beam, this can be done duringthe casting of the beam. The bridge element is mounted movably insidethe box element, preferably in such a manner that in a retractedposition it is located completely inside the box element.

According to an aspect of the invention the first part may also comprisean anchor element extending a distance out from an outer end of thebridge element and working in conjunction with a locking element in thesecond part in order to interlock the parts in a joined condition,thereby providing a tension anchoring of the system. The joining systemmay furthermore comprise devices for restricting the movement of thebridge element relative to the box element to a maximum extendedposition, thereby preventing the bridge element from being moved furtherout than to the stopper device without further manipulation. The joiningsystem may comprise devices on the box element and/or the bridge elementwhich provide easy movement of the bridge element relative to the boxelement both from a retracted to an advanced position but also from anadvanced position to a retracted position. This may be implemented bymeans of guide rope, openings in the box element, the shape of thebridge element, etc.

The invention also comprises a method for joining two building elementssuch as, for example, a landing slab in a staircase, where a number ofbox elements are mounted in the first building element, the landingslab, by casting the landing slab, where an open side of the boxelements is arranged in alignment with an edge of the landing slab andwhere there is access in an upper side of the landing slab to a numberof attachment portions of lifting elements secured to the cast boxelements. In the second building element, the staircase, there areprovided corresponding cutouts in proportion to the box elements,whereupon bridge elements are mounted in the box elements, the liftingequipment is secured to the attachment portions and lifted forpositioning. When the open end of the box elements is located outsidethe cut-out, the bridge element is moved to an extended position withthe result that a portion of the bridge element is located inside thecut-out, and the landing slab is lowered until the bridge element abutsagainst a surface of the cut-out, whereupon the lifting equipment caneasily be released from the stair landing.

The method may furthermore comprise placing a seal in the form of asealing element along a lower edge and/or upper edge of the gap betweenlanding slab and staircase, and grouting compound is filled in thecavity in the first and second parts of the joining system and the gapand simultaneously in the recessed portion round the attachment portionof the lifting elements, with the result that all cavities in thejoining system are filled, forming a smooth surface for the stairlanding. A corresponding method will also be employed for, for example,a beam and a pillar. By means of these steps the joining system isanchored against movement in a normally horizontal plane.

The invention will now be explained by a non-limiting embodiment withreference to the attached drawings, in which;

FIG. 1 is a perspective view of a first part for securing to orincorporation in a first building element,

FIG. 2 illustrates the device in FIG. 1 viewed from above,

FIG. 3 illustrates the device in FIG. 1 viewed from the side,

FIG. 4 is a perspective view of the box element in FIG. 1 alone,

FIG. 5 is a perspective view of the box element in FIG. 1 alone,

FIG. 6 is a partial view of two building elements joined by a joiningsystem according to the invention, and

FIG. 7 is a side view of the system in FIG. 6.

In FIG. 6 a joining system according to the invention is illustrated inuse for joining a first building element 1 and a second building element2. The building elements are shown before grouting a space 6 between theelements and a possible recessed portion 4.

A first part 10 of the joining system attached in or to the firstbuilding element 1 is illustrated in FIGS. 1-3. This first part 10comprises a box element 100, a lifting element 110 and a bridge element120. The box element 100 with the lifting element is further illustratedin FIG. 4 and the bridge element 120 is shown in FIG. 5. The box elementcomprises a first and a second side wall 101, 102 connected via a bottomwall 103 and a top wall 104, thereby forming an internal cavity 107 inbetween these walls. This internal cavity 107 has an open end 108 and anend closed by an end plate 105. At the internal end plate 105, moreover,an access opening 106 is provided leading into the internal end of theinternal cavity. This access opening is composed of a hole in the topwall 104 which cooperates with an opening plate 109, which is bent intoa U-shape where the tops of the U are connected to the end plate 105 andan end section of the U connected to the top wall 104, where a secondend section of the U will be aligned with a main surface 31 of an outerside 3 of an building element 1.

The lifting element 110 comprises an attachment portion 111 comprising aconical extension 114 and a top flange 115, best illustrated in FIG. 3,which conical extension is connected at its end opposite the top flangewith a connecting rod 113, where the connecting rod 113 has a smallercross section than the top flange 115, with the result that the conicalextension goes from a smaller cross section at the connecting rod 113 toa larger cross section at the top flange 115. At the end opposite theattachment portion 111, the connecting rod 113 is connected to a fixingplate 112, secured to the top wall 104 of the box element 100.

The bridge element 120 is also composed of two side walls 121, 122 and abottom wall 123 and a top wall 124, as illustrated in FIG. 5, therebyforming an internal open cavity 125. The bottom wall 123 is furtherprovided with a first thickening portion 126 a and a second thickeningportion 126 b, arranged with a space 127 along the bottom wall 123 ofthe bridge element 120. It is also conceivable for this thickeningportion to be a whole plate or the like, and it may be a plate ofuniform or varying thickness. The bridge element 120 comprises aninternal end 128 arranged facing into the box element 100, where arestricting device 130 is mounted at the internal end 128. There isaccess to this restricting device 130 via the access opening 106 in thebox element 100, as illustrated in FIG. 2. It can also be seen here thatthe bridge element 20 illustrated in FIG. 5 is rotated 180 degrees abouta substantially horizontal axis relative to the bridge element which isdepicted joined to the box element in FIGS. 1-3. This restricting device130 may be a threaded hole for screwing in a stopper element (not shown)which prevents the bridge element 120 from being pulled out beyond amaximum extended position relative to the box element without furthermanipulation of the elements, such as unscrewing the stopper elementagain. The bridge element 129 also comprises an outer end 129 locatedoutside the box element 100 in an extended position of the bridgeelement, but which in a retracted position is located substantially ator inside the open end 108 of the box element 100.

As illustrated in FIGS. 6 and 7, when the first part 10 is mounted inthe first building element 1, the attachment portion 111 of the liftingelement 110 will be located outside an outer side 3 of the buildingelement 1. This outer side 3 is composed of a main surface 31 located inan outer plane 30 composed of the building element 1 and a partialsurface 32 composed of a recessed portion 4 of the building element 1.This recessed portion 4 therefore forms a cut-out in the main surface 31of the building element, and this recessed portion 4 may be providedwith guide devices 5, such as for example a partly spherical shape ofthe recessed portion 4. An end section of the opening plate 109 formingthe access opening 106 is aligned with the main surface 31 of thebuilding element 1. The open end 108 of the box element 100 is alignedwith a side wall 7 of the first building element 1 facing the secondbuilding element 2. The bridge element 120 has its outer end 129arranged inside a cavity 21 composed of the second part 20 of thejoining system. In a bottom of this cavity 21 there may be provided abase plate 22. For completion of the joining process, the space 6between the two building elements 1, 2 will be sealed in the lower edgeand grouting compound will be added to the space in order to fill outthe cavity 21 and the cavity 125 of the bridge element 120 and thecavity 107 and the access opening 106 of the box element 100, where therecessed portion 104 will also be filled with grouting compound, therebyforming a smooth surface for the building element 1. The access openingmay be employed for moving the bridge element from a retracted positionto an advanced position.

The invention has now been explained with reference to an embodiment.Many variants of this embodiment may be envisaged within the scope ofthe invention as defined in the following claims. In one variant thelifting element may comprise a fixing plate that forms a U-shapecomplementary to the box element's outer shape, where the fixing plateis secured to the box element by U-shaped legs. The lifting element mayalso be designed without a fixing plate, where the actual connecting rodis secured directly to the box element, to the top wall or, for example,to a side wall of the box element. In this case two lifting elements mayalso be affixed to the box element, one to each side wall of the boxelement. These two lifting elements may be arranged in a common recessedportion relative to a main surface of the building element. Variants mayalso be envisaged where features are employed from some embodimentstogether with features from other embodiments such as a sleeve-shapedfixing plate with a connecting rod secured to two opposite sides of thesleeve-shaped fixing plate, each with an attachment portion in eachrecessed portion. In another variant the two connecting rods may beconnected to a common attachment portion located in a recessed portionof the building element, thereby forming a loop device as an attachmentportion.

1. A joining system for securing a first building element (1) relativeto a second building element (2), where a first part (10) of the joiningsystem is adapted for mounting on one building element (1) and a secondpart (20) of the joining system is adapted for mounting on the secondbuilding element (2), which first part (10) comprises a box element(100) adapted to be cast in one of the building elements (1,2),characterised in that a lifting element (110) is secured to the boxelement (100), which lifting element (110) comprises an attachmentportion (111) adapted for cooperation with lifting equipment, whichattachment portion (111) during an installation phase of the joiningsystem is located relatively outside an outer side (3) of one of thebuilding elements (1, 2) comprising the box element (100).
 2. A joiningsystem according to claim 1, characterised in that the attachmentportion (111) comprises devices (114, 115) for rapid coupling with alifting equipment.
 3. A joining system according to claim 1,characterised in that the lifting element (110) comprises a fixing plate(112), and a connecting rod (113) connected to the outer attachmentportion (111), where the fixing plate (112) is secured to the boxelement (100) and is connected to the connecting rod (113).
 4. A joiningsystem according to claim 3, characterised in that the fixing plate(112) forms a sleeve element, which is arranged round the box element(100).
 5. A joining system according to claim 1, characterised in thatin a utilisation condition, the attachment portion (111) is located in aportion (4) of the building element (1) to which it is mounted, whichportion is recessed relative to the surface (3).
 6. A joining systemaccording to claim 5, characterised in that the recessed portion (4)comprises devices (5) for guiding lifting equipment into engagement withthe attachment portion (111).
 7. A joining system according to claim 5,characterised in that the attachment portion (111) is mounted within aplane (30) aligned with a main surface of the outer side (3) wherein itis located, with the result that the attachment portion (111) does notprotrude beyond the building element's outer circumference.
 8. A joiningsystem according to one of the above-mentioned claims, characterised inthat the box element (100) is a substantially hollow element with anopen end (108) aligned with a side (7) of the building element (1) whichafter mounting will face the second building element (2), where a bridgeelement (120) is mounted movably internally in the box element (100)from a substantially retracted position where it is located inside thebox element (100) to an extended position where a portion of the bridgeelement is located outside the box element (100) and can go intoengagement with a receiving opening (21) in the second building element(2), thereby interconnecting the building elements (1,2).
 9. A joiningsystem according to one of the above-mentioned claims, characterised inthat the building element (1) comprising the box element (100) and thelifting element (110) is a cast building element (1).
 10. A method forjoining two building elements (1, 2), whereof at least one buildingelement (1) is a cast element, characterised in that the desired numberof box elements (100) is provided, to which the desired number oflifting elements (110) is attached, the box elements (100) with thesecured lifting elements (110) are arranged in a casting mould with theresult that after casting the attachment portion (111) of the liftingelement (110) will be located outside an outer surface (3) of thebuilding element (1), grouting compound is added to the casting mouldand the building element (1) is set and brought to the user site, thebridge element (120) is placed in a retracted position inside the boxelement (100), lifting equipment is secured to the attachment portion(111) of the lifting element (110) and the building element (1) islifted up to its position and joined by guiding the bridge element (120)to an extended position in engagement with the second building element(2), whereupon the lifting equipment is released from the first buildingelement (1).
 11. A method according to claim 10, characterised in thatthe attachment portion (111) is located in a portion (4) which isrecessed relative to the rest of the outer circumference of the buildingelement, which recessed portion (4) is grouted after joining of thebuilding elements (1, 2), thereby forming a smooth outer surface of thebuilding element (1).